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Windows 7: AHCI : Enable in Windows 7 / Vista

AHCI : Enable in Windows 7 / Vista

AHCI Advanced Host Controller Interface makes NCQ Native Command Queing along with hot-plugging or hot swapping through SATA Serial-ATA host controllers possible; Vista was the first to offer this feature. The issue with AHCI is it needs to be enabled in the BIOS prior to OS installation; doing so after you have installed the OS will disable the PC. The reason why is Windows disables the AHCI drivers not needed durring installation.

This tutorial will show you how to enable AHCI after you have installed the OS if you didn't already have AHCI enable in the BIOS when you installed the OS.

Warning

Changing values in the Windows registry can disable your machine; if you're not sure how to do this please post a question in this tutorial and someone will be glad to help you.

Note

This method will also work for Windows Vista though the default DWORD string value in Vista will be "4" where it will be "3" in Windows 7.

As a precaution it would be a good idea to create a "System Restore Point" before you start this, the tutorial can be found at the link below.

For those with nForce boards, this method was worked out by Everlong and credit for that goes to him, thanks mate!

Just to put in here for nForce users, nForce boards do not support AHCI (with the exception of nForce boards that include onboard graphic cards), and also don't send the TRIM command for SSDs. It can do NCQ through its controller though. The JMicron SATA ports do support AHCI, but you'd get worse performance running a HDD through these, than on the normal SATA ports.

You can uninstall the Nvidia controller though in Device Manager and install Microsoft's IDE Controller, which can send TRIM commands for SSDs.

Head to Device Manager (Open Start menu, type Device Manager), and click "IDE ATA/ATAPI Controllers", and you will see 3 Nvidia Serial ATA Controllers. Right click one of them and click "Properties" and go to the "Driver" tab. Click "Update Driver". Click "Browse my Computer", and then "Let me pick". You will see the option to choose "Standard Dual Channel PCI IDE Controller". Click this and click "Next" and let it install.

Do the same for the other two Nvidia Controllers in Device Manager and restart your system. After the controllers have installed, you will be asked to reboot again.

SSDs will now have a slight performance boost with the TRIM command, and also regular HDDs also have a slight increase as well.

Step 3 is not too clear since your talking about pressing r in right pane and dont mention which entry that is since its covered by the menu. I assume you mean "Start" but in my case its already set at 0 since I enabled AHCI in bios so I assume I dont need this?

Step 3 is not too clear since your talking about pressing r in right pane and dont mention which entry that is since its covered by the menu. I assume you mean "Start" but in my case its already set at 0 since I enabled AHCI in bios so I assume I dont need this?

Hello Nick.

It says above to "In regedit navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services, click msahci, in the right pane r. click "start" then click "modify" ...

AHCI : Enable in Windows 7 / Vista

Enable and/or Disable AHCII hope I am not duplicating something here. . . . I did look - Honest!
I ran into an interesting problem and found an easy fix.
First: I wanted to ENABLE AHCI because (supposedly) it improves HDD performance. (It also enables a host of other interesting features.)
I discovered the...

Hardware & Devices

AHCI : Enable in Windows XP after OS installFor info on other OS's take look here:
https://www.sevenforums.com/tutorials/61869-ahci-enable-windows-7-vista.html
You can use this method on Legacy BIOS or uEFI/BIOS firmware.
For this example I am using a PC with uEFI/BIOS firmware & Secure Boot DISABLED.
With a Intel Chip Set.
...

Tutorials

enable AHCI in Windows 7hi...
i found several tutorials to enable the AHCI-driver in win7/vista but the registry keys don't match mine...
the tutorial is as following:
1. Exit all Windows-based programs. 2. Click Start, type regedit in the Start Search box, and then press ENTER. 3. If you receive the User Account...

Hardware & Devices

Windows 7...>SSD....Enable AHCI B4 InstallationOkay I plan on doing a clean install of Windows 7 on my laptop. I have an SSD from crucial.
I know that I need to enable AHCI BEFORE I start the installation of Windows 7...correct?
Now....I saw this Intel website in regards to AHCI.
Intel® Rapid Storage Technology &mdash; Configure the...

Installation & Setup

AHCI to Enable or Not?Hi, I am using a HP Pavillion 180t computer with Window 7(SP-1), IE9 RC. 12GB Ram, Quad Core i7, 3.33Ghz.
I do not have AHCI enabled based upon the Tutorial to do so. Would enableing AHCI be of value to me? If so how? Any help appreciated.